Watts' confessions emerged during an interview with police re-investigating the evil pair over another murder. They have grilled Watts and Beck independently over the disappearance of Helen Mary Feeney, last seen in October 1987.

Mrs Feeney is classed as a missing person, as her body has never been found.Watts has denied any involvement with her murder.

Mrs Feeney, a mother of a young boy, disappeared during the couple's eight-week crime spree in 1987.